smk->cur_frame++;
smk->nextpos = avio_tell(s->pb);
} else {
+ if (smk->stream_id[smk->curstream] < 0)
+ return AVERROR_INVALIDDATA;
if (av_new_packet(pkt, smk->buf_sizes[smk->curstream]))
return AVERROR(ENOMEM);
memcpy(pkt->data, smk->bufs[smk->curstream], smk->buf_sizes[smk->curstream]);